Centrifugal screen



Oct. 27, 1925- 1,559,528

H. STUB CENTRI FUGAL SCREEN Filed June 26, 1925 Patented Oct. 27, 1925.

UNITED STATES PATENT OFFICE.

HANS STUB, OF OSLO, NORXVAY.

Application filed June 26, 1925.

To all whom it may Concern:

e it known, that l, llANs S'rb'n, subjeft of the King ot Norway,residing; at Kirle- Veien 78, Oslo, Norway, have invente l certain newand useful l mprovements in tlentrituga] tereens; and I (lo hereby(leelare the following to be a full, elear, and exact. (le Seription o'ithe invention, such as wiil enable others SllllCtl in the art to whichit appertains to i ial e and use the same, reieronte being had to theaccompanying' tlrawings, aml to letters or ligures ot reference markedthereon, Which form a part of this speeiliea tion.

ln Centril ugal sereens l or sorting wood pulp (paper pulp) into eoarseand fine libres it is important to obtain a substantially perl eetlyUniform supply ot the pulp water t-o the Screening eylimler preterablyin a tangential tliret'tion, because in such case no listurbanees ol thehel tai movement ol the pulp water over the eylimler will ltllx'C plaeeor same Will be retlueetl to a minimum. In the type of sereens, wliereinthe pulp is supplied inside the (fentri'l ugal wheel or to the Wings,such a unitorm tangential supply is (liflieult to peri orm. lut it mightbo ob tained by eausing the pulp to tale a rot'ating motion and in thisstate to supply itat: the end ot the sereenin (ylinder, bel ore it iseaught by the eentritugal Wheel proper. (hu) has trietl to obtain thisresult by supplyin; the pulp to the eylinler by a separate wheelconstruct-ed mproximately like the wheel of a centriugnl pump andmountel on the same shaft' as the eentritugal Wheel.

However, in order to obtain a quite uni- .torm outllow troni the pumpwheel, it is neeessary :hat the wheel ehannels be eom pletely lilletl bypulp water, which in turu Pan bo ottet'tel only It the outlow lhere'trom takes pla'e in water liqui l) not in air and that the outtlowaperturi: ot the pump, Whieh l orms also the supply to the srreeningeylinder, be a eireular aperture (oneentrie with the Said eylinder.

In the present nvention the Conditions above named are fulfilled byarranging on the blade shatt, adjarent the supply to the Screeningeylinder, a dise Which is provided at the supply side with pnmp bladessurrounded by a Curved tight detleetion wall, the largest inner(liameter of Which is larger Seral NO. 89,307.

than the tlltll1t`ti`l` :xi satl wall tormihg t to the sereeuing ey siloto the supply.

Preferably the punp blules on the l`* ply side of the rulial (lis mayonstitut" eontinuous extension ot the tntril ng i blates which rorotatin' lit i(l() the s I'(-(` ing eylintler proper.

[in embodiment ot the in ention is illus tratel in the areompanyingdrawing, show ing a longittnlinal section ol the eompete apparatus.

1 (lesignates -he pulp supply, the punp Wheel blades or wings, the hub(lise ol the pump wheel, l' the pump easing, 5 the screening eylinder,the eentritunal wlieei, i" the outlet .for the line lillered pulp alul 8the out# let lor the (oarse pulp (mill pulp, reliuer pulp).

'l'he pump Wheel thus eomprises the lmb (lise i, being ol approximatelythe same (iiameter as the Screening (ylintler, and the Wingb extemling a(listanee l arther out. Thepump wheel l thereby will be larger in(liameter than the Screening (ylil'nler. AS a consequence thereol whenthe machine is in operation, a mueh larger quantity o' liquil mustrotate in the exterior part ol' the pump easing. (won il the supply isvery small.

Now, the hub (lista of the pump Wheel 'is made so large that itsexterior edge in all vases projects somewhat down into the ro tatingliquiil. 'thereby the air is preventel from passing` baok into the pmnpChannels, eohsequentty the Said Channels Will remain quite tilled withpulp Water. The Veloeity through the ehannels Will thereby be as Nearlyas possible ol the same Value :ill over at the same (listam'e l rom theCentre alul may bo regulatod by a elosinr member arrmgetl in the supplypipe.

i ron the pulp water rotating within the exterior part of the pumpCasing` a Uniform Current pusses on to the sereening eylimler, and thequantity may be regulated Within \Vide limits by the Said closing memberin the supply pipe.

lt will be obvious that the rotation Velocity of the pulp water, whenentering the cylinder, will be approximately the same one as that of thecentrifugal member.

Therel lOSSeS due to shecks Will he avoidvd and a nlObt pessihlyunitornl motion &long the screen is obtained.

ln the einbodiment described above, the wall 4 surrounding the puinpblades is btationary, but ohvieusiy nothing prevenir-1 being constructedas a rotating member. in the latter case 'the \Vall l is connected inSome suitable manner with the hlales :l Or With the rotating` Shat t asOrdii'Iarily uSed in centrifngal plnnps.

Claims:

l. 'l he coinhinatien with a 'entril ugal screen ceniprising` aherizuntally arranged Screening cylinder, retating hiades within Saidcylinder and an axial supply, nl a rotating (lisc Spaced i ruin said cyinder at the supply end thereet, punlp l l2(l0$ at the Supply side ofsaid disc, a housing enclosing said diSc, the Outer end of said houingbeing adaptecl te receive the material to be screened and the inner endet Said housing alnltting the supply end (it Said screen.

2. The inVentiOn as claimed in claim l, Wherein the dianleter Of saiddisc is net es than the (li nnetcr et' Said screen.

'lhe inrentiun as cainhd in claim l, wherein the lll l dic is enntedupon the Bhatt carrying Said rotating hlades.

'l he lnwntinn is claimed in claim l, \Vherein the pnnp hlades en Saiddisc extend (H'Ql' the edg e thereO and nlerge int) the re Specii-,eretating hlades.

'lhe invention as claimed in claim l, \Vherein the largcet innerdiameter el Said housing S greater than the (lian eter ol Said screen.

ln tcstiinony that l claim the foregoing as my inventifln, 'l havesigned ny name.

HANS STUE.

